This invention relates generally to firearms, and more particularly to stock or conversion kits (a.k.a. “bullpup stock kit”, “bullpup stock system”) which convert a traditional firearm into bullpup configurations.
Firearm “bullpup” configurations are discussed in some detail in Wikipedia, some portions paraphrased, summarized, and or quoted herein. Traditionally, firearms using detachable magazines are configured so that fee action of the firearm and fee ammunition magazine are located in front of the trigger. Firearms configured so that the action and the magazine are located behind the trigger of fee firearm are generally referred to as “bullpups”.
Bullpup configuration permits a shorter overall weapon for a given barrel length. This is due to the positioning of the action closer to the rear end of the buttstock. This maintains the advantages of a longer barrel in muzzle velocity and accuracy, while improving maneuverability and reducing weight.
Traditional firearms users may desire to alter the appearance and function of their more traditionally configured firearm into that of a bullpup for various reasons, including but not limited to improve ergonomics, reduce weight, and reduce overall length without compromising ballistic performance. There is a need for a conversion system that minimizes the requisite expertise and mechanical skill.
In converting a firearm to bullpup configuration, the action and the mounting position of the ammunition magazine are moved rearward relative to the butt, but the desired position of the trigger relative to the butt stays the same. This requires the bullpup stock kit to include a mechanism that places an auxiliary trigger relatively in front of the action and in operational communication with the firearm's original trigger (aka the trigger of a barreled action). The foregoing is usually accomplished with a rigid push-rod type linkage mechanism. The trigger pull characteristics of these mechanisms is generally considered inferior to the trigger pull characteristics of the host firearm. The present invention achieves an advantage over existing systems by providing a tension-type trigger linkage mechanism utilizing a cable.
One handed operation is desirable. The compact design of the bullpup configuration entices users to attempt one handed operation. However, traditional bullpup designs are problematic in that the pull length is too long for efficient one-handed operation. “Pull length” is generally defined as the distance from the center of the buttstock to the trigger. Thus, it is an object of this invention to reduce the pull length.
An advantage of the present invention is achieved by providing a uniquely designed buttstock resulting in a reduced pull length; a forwardly sloping butt design achieves a shorter pull length by allowing the upper portion of the butt to rest on the shoulder or upper arm of the user, thus improving one-handed operation.
Due to the rearward placement of the firearm action relative to the butt in a bullpup configured firearm, a mechanism that places an auxiliary cocking handle forward of the action and in operational communication with the firearm's original cocking handle is a desirable feature. Also, due to the rearward placement of the firearm action relative to the butt in a bullpup configured firearm, the original sights cannot be used. Thus, it is desirable to provide auxiliary sights or an attachment platform for auxiliary sights.
Another advantage is achieved by connecting the auxiliary sights and/or the attachment platform for the auxiliary sights directly to the firearm receiver, because doing so provides a more stable and therefore accurate arrangement.
Yet another advantage is achieved by combining the aforementioned auxiliary cocking handle and attachment platform for auxiliary sights into an assembly that is connected directly to the receiver. This arrangement achieves the aforementioned advantages as well as requiring less volume and mass than would be needed for the separate components.
In the various embodiments described, the present invention is advantageous in that it requires minimal gunsmithing knowledge or mechanical expertise to install, provides a configuration that conforms to the shoulder or upper arm and places the firearm action close to the body and shortens the pull length, provides an auxiliary trigger forwardly positioned in front of the action and the magazine, provides a an auxiliary cocking handle forwardly positioned in front of the action, and provides a stable mounting platform for auxiliary sights.
In one embodiment, a bullpup conversion system comprises, a grip adapted to be gripped by a user in such a way so as to allow the user to engage an auxiliary trigger; a trigger linkage mechanism operatively engaging the auxiliary trigger and a first trigger of a barreled action, wherein the linkage mechanism includes a cable; the grip and auxiliary trigger being located in front of the barreled action; a trigger safety for restraining the auxiliary trigger in a non-firing position; a butt having a rearwardly oriented surface adapted to conform to the upper surface of the operator's shoulder-upper arm region; a sight and/or scope accessory mounting rail; a cocking handle linkage mechanism having an auxiliary cocking handle for operatively engaging a first cocking handle; wherein the sight and/or scope accessory mounting rail and cocking handle linkage mechanism comprise an assembly (aka a combined system); the foregoing enclosed within a two piece chassis system. It is to be understood that the term “chassis”, as used herein, is interchangeable with, and in the nature of, an “enclosure” and thus is not limited in meaning to a frame or subframe.
In one embodiment, the present invention is configured to work with a Ruger 10/22 rifle (“Ruger” and “10/22” are trademarked). Accordingly, those of skill in the art will appreciate that the various components described herein are sized accordingly. In one embodiment, a bullpup conversion system comprises, left and right chassis portions configured to receive the barreled action of a rifle (e.g. Ruger 10/22 rifle).
In one embodiment, the rear portion of the chassis comprises a butt with a concave contoured surface that is angled forward from top to bottom. This configuration allows the rear end of the stock to rest on the upper surface of the operator's shoulder or arm and also reduces the pull length, over traditional butt designs for a given overall stock length. A rail is secured to the top of the receiver using a connector plate that is secured to the factory installed scope mount holes. The rail provides a mechanism that connects auxiliary cocking levers on either side of the rail to the cocking handle on the barreled action. By operating either auxiliary cocking handle, the cocking handle on the barreled action may be operated.
It is to be understood that the term “action” as used herein throughout includes the bolt, receiver and trigger mechanism of the firearm. The firearm used in some embodiments is a Ruger 10/22 rifle, commonly referred to as a 10/22. The 10/22 is typically chambered to fire .22 Long Rifle caliber ammunition.
As described herein, the present invention is directed towards a firearm stock kit that may be used to convert a traditionally configured firearm into bullpup configuration. The stock incorporates a uniquely configured buttstock that conforms to the operator's shoulder or upper arm and reduces the pull length for a given overall stock length. The firearm stock kit also provides for an auxiliary trigger, an integrated cocking and accessory mounting rail, and a trigger safety. Those of skill in the art will appreciate other objects and advantages in addition to those described herein.